This invention relates to powder metallurgical manufacturing methods for making accurately shaped artificial tooth restorations having an individually manufactured core of a densely sintered, high-strength ceramic material, which fits against prepared tooth surfaces or artificial abutments. On these cores, dental porcelain can be fired to form tooth crowns, inlays, veneers or bridges.
U.S. Pat. No. 5,080,589 discloses a method of manufacturing copings of densely sintered, high-strength ceramic material where the sintering shrinkage is considered. According to this patent, the copings are premanufactured which means that they have been sized before sintering to compensate for shrinkage.
U.S. Pat. No. 5,106,303 and Swedish Patent 469,057 disclose manufacturing of inlays, onlay crowns and veneers of densely sintered, high-strength ceramic material by copy milling a green, a presintered or sintered body from an impression of the prepared tooth surface and considering the sintering shrinkage.